Question: Michael is 78 years old and Kevin is 16 years old. How many years will it take until Michael is only 3 times as old as Kevin?
We can use the given information to write down an equation about how many years it will take. Let $y$ be the number of years that it will take. In $y$ years, Michael will be $78 + y$ years old and Kevin will be $16 + y$ years old. At that time, Michael will be 3 times as old as Kevin. Writing this information as an equation, we get: $78 + y = 3 (16 + y)$ Simplifying the right side of this equation, we get: $78 + y = 48 + 3 y$ Solving for $y$ , we get: $2 y = 30$ $y = 15$.